U. S. 1). A., P.. E. r.nl. C.S, Part TX. D. F. I. I.. February 11, 1909. 



PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



THE PEACH-TREE BARKBEETLE. 



(PhloEotribiis liiniiitiris Ilarr.) 



By H. F. WiLSox, 

 Engaged in Deciduous Fruit Insect Investigations. 



INTRODUCTION. 



By way of introduction it is perhaps necessary to give an account 

 of the present degree of importance, from an economic standpoint, 

 which this beetle has reached in northern Ohio. For the last four 

 or five years this insect has been doing a great amount of injury to 

 apparentl}^ healthy trees. The history of Scolytida^ in general shows 

 that certain species may be present in orchards for years without 

 doing anj'^ appreciable damage. Then, owing to favorable climatic 

 or other conditions, they may develop in large numbers and accom- 

 plish considerable injury. Such seems to be the history of Phlmo- 

 tribus limiiiaris. 



The attention of Prof. H. A. Gossard, of the Ohio Agricultural 

 Experiment Station, was called to this insect by Mr. "\Y. H. AVright, 

 in charge of a large farm at Lakeside, Ohio, Mr. Wright having 

 reported to him that large blocks of peach trees in the orchard were 

 dying from an unknown cause. Upon investigation Professor Gos- 

 sard found that this orchard was seriously infested with Phlceotrihits 

 Uminaris. 



At the instance of Professor Gossard, investigation of this species 

 was undertaken in the spring of 1908 by the Bureau of Entomology 

 in cooperation with the Ohio Agricultural Experiment Station, and 

 the writer, representing the Bureau, and Avorking under the joint 

 direction of Professors Gossard and Quaintance, was assigned to 

 the work, with headquarters at Lakeside, Ohio. Through the courtesy 

 of Mr. Wright a suitable building and experimental orchards were se- 

 cured. All breeding cages were kept under out-of-door conditions, 

 and as far as possible outside conditions were watched in comparison 

 with those in the breeding cages. Data were secured on all stages of 

 development of the insect, and the results obtained^ are considered 



fairly complete for a single season's work. 



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